forked from grate-driver/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
amiserial.c
2156 lines (1861 loc) · 53 KB
/
amiserial.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* linux/drivers/char/amiserial.c
*
* Serial driver for the amiga builtin port.
*
* This code was created by taking serial.c version 4.30 from kernel
* release 2.3.22, replacing all hardware related stuff with the
* corresponding amiga hardware actions, and removing all irrelevant
* code. As a consequence, it uses many of the constants and names
* associated with the registers and bits of 16550 compatible UARTS -
* but only to keep track of status, etc in the state variables. It
* was done this was to make it easier to keep the code in line with
* (non hardware specific) changes to serial.c.
*
* The port is registered with the tty driver as minor device 64, and
* therefore other ports should should only use 65 upwards.
*
* Richard Lucock 28/12/99
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
* 1998, 1999 Theodore Ts'o
*
*/
/*
* Serial driver configuration section. Here are the various options:
*
* SERIAL_PARANOIA_CHECK
* Check the magic number for the async_structure where
* ever possible.
*/
#include <linux/delay.h>
#undef SERIAL_PARANOIA_CHECK
#define SERIAL_DO_RESTART
/* Set of debugging defines */
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
/* Sanity checks */
#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
tty->name, (info->flags), serial_driver->refcount,info->count,tty->count,s)
#else
#define DBG_CNT(s)
#endif
/*
* End of serial driver configuration section.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/serial_reg.h>
static char *serial_version = "4.30";
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/console.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <asm/setup.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
#define custom amiga_custom
static char *serial_name = "Amiga-builtin serial driver";
static struct tty_driver *serial_driver;
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
static struct async_struct *IRQ_ports;
static unsigned char current_ctl_bits;
static void change_speed(struct async_struct *info, struct ktermios *old);
static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
static struct serial_state rs_table[1];
#define NR_PORTS ARRAY_SIZE(rs_table)
#include <asm/uaccess.h>
#define serial_isroot() (capable(CAP_SYS_ADMIN))
static inline int serial_paranoia_check(struct async_struct *info,
char *name, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
static const char *badmagic =
"Warning: bad magic number for serial struct (%s) in %s\n";
static const char *badinfo =
"Warning: null async_struct for (%s) in %s\n";
if (!info) {
printk(badinfo, name, routine);
return 1;
}
if (info->magic != SERIAL_MAGIC) {
printk(badmagic, name, routine);
return 1;
}
#endif
return 0;
}
/* some serial hardware definitions */
#define SDR_OVRUN (1<<15)
#define SDR_RBF (1<<14)
#define SDR_TBE (1<<13)
#define SDR_TSRE (1<<12)
#define SERPER_PARENB (1<<15)
#define AC_SETCLR (1<<15)
#define AC_UARTBRK (1<<11)
#define SER_DTR (1<<7)
#define SER_RTS (1<<6)
#define SER_DCD (1<<5)
#define SER_CTS (1<<4)
#define SER_DSR (1<<3)
static __inline__ void rtsdtr_ctrl(int bits)
{
ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
}
/*
* ------------------------------------------------------------
* rs_stop() and rs_start()
*
* This routines are called before setting or resetting tty->stopped.
* They enable or disable transmitter interrupts, as necessary.
* ------------------------------------------------------------
*/
static void rs_stop(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_stop"))
return;
local_irq_save(flags);
if (info->IER & UART_IER_THRI) {
info->IER &= ~UART_IER_THRI;
/* disable Tx interrupt and remove any pending interrupts */
custom.intena = IF_TBE;
mb();
custom.intreq = IF_TBE;
mb();
}
local_irq_restore(flags);
}
static void rs_start(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_start"))
return;
local_irq_save(flags);
if (info->xmit.head != info->xmit.tail
&& info->xmit.buf
&& !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
}
local_irq_restore(flags);
}
/*
* ----------------------------------------------------------------------
*
* Here starts the interrupt handling routines. All of the following
* subroutines are declared as inline and are folded into
* rs_interrupt(). They were separated out for readability's sake.
*
* Note: rs_interrupt() is a "fast" interrupt, which means that it
* runs with interrupts turned off. People who may want to modify
* rs_interrupt() should try to keep the interrupt handler as fast as
* possible. After you are done making modifications, it is not a bad
* idea to do:
*
* gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
*
* and look at the resulting assemble code in serial.s.
*
* - Ted Ts'o (tytso@mit.edu), 7-Mar-93
* -----------------------------------------------------------------------
*/
/*
* This routine is used by the interrupt handler to schedule
* processing in the software interrupt portion of the driver.
*/
static void rs_sched_event(struct async_struct *info,
int event)
{
info->event |= 1 << event;
tasklet_schedule(&info->tlet);
}
static void receive_chars(struct async_struct *info)
{
int status;
int serdatr;
struct tty_struct *tty = info->tty;
unsigned char ch, flag;
struct async_icount *icount;
int oe = 0;
icount = &info->state->icount;
status = UART_LSR_DR; /* We obviously have a character! */
serdatr = custom.serdatr;
mb();
custom.intreq = IF_RBF;
mb();
if((serdatr & 0x1ff) == 0)
status |= UART_LSR_BI;
if(serdatr & SDR_OVRUN)
status |= UART_LSR_OE;
ch = serdatr & 0xff;
icount->rx++;
#ifdef SERIAL_DEBUG_INTR
printk("DR%02x:%02x...", ch, status);
#endif
flag = TTY_NORMAL;
/*
* We don't handle parity or frame errors - but I have left
* the code in, since I'm not sure that the errors can't be
* detected.
*/
if (status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE)) {
/*
* For statistics only
*/
if (status & UART_LSR_BI) {
status &= ~(UART_LSR_FE | UART_LSR_PE);
icount->brk++;
} else if (status & UART_LSR_PE)
icount->parity++;
else if (status & UART_LSR_FE)
icount->frame++;
if (status & UART_LSR_OE)
icount->overrun++;
/*
* Now check to see if character should be
* ignored, and mask off conditions which
* should be ignored.
*/
if (status & info->ignore_status_mask)
goto out;
status &= info->read_status_mask;
if (status & (UART_LSR_BI)) {
#ifdef SERIAL_DEBUG_INTR
printk("handling break....");
#endif
flag = TTY_BREAK;
if (info->flags & ASYNC_SAK)
do_SAK(tty);
} else if (status & UART_LSR_PE)
flag = TTY_PARITY;
else if (status & UART_LSR_FE)
flag = TTY_FRAME;
if (status & UART_LSR_OE) {
/*
* Overrun is special, since it's
* reported immediately, and doesn't
* affect the current character
*/
oe = 1;
}
}
tty_insert_flip_char(tty, ch, flag);
if (oe == 1)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
tty_flip_buffer_push(tty);
out:
return;
}
static void transmit_chars(struct async_struct *info)
{
custom.intreq = IF_TBE;
mb();
if (info->x_char) {
custom.serdat = info->x_char | 0x100;
mb();
info->state->icount.tx++;
info->x_char = 0;
return;
}
if (info->xmit.head == info->xmit.tail
|| info->tty->stopped
|| info->tty->hw_stopped) {
info->IER &= ~UART_IER_THRI;
custom.intena = IF_TBE;
mb();
return;
}
custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
mb();
info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
info->state->icount.tx++;
if (CIRC_CNT(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
#ifdef SERIAL_DEBUG_INTR
printk("THRE...");
#endif
if (info->xmit.head == info->xmit.tail) {
custom.intena = IF_TBE;
mb();
info->IER &= ~UART_IER_THRI;
}
}
static void check_modem_status(struct async_struct *info)
{
unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
unsigned char dstatus;
struct async_icount *icount;
/* Determine bits that have changed */
dstatus = status ^ current_ctl_bits;
current_ctl_bits = status;
if (dstatus) {
icount = &info->state->icount;
/* update input line counters */
if (dstatus & SER_DSR)
icount->dsr++;
if (dstatus & SER_DCD) {
icount->dcd++;
#ifdef CONFIG_HARD_PPS
if ((info->flags & ASYNC_HARDPPS_CD) &&
!(status & SER_DCD))
hardpps();
#endif
}
if (dstatus & SER_CTS)
icount->cts++;
wake_up_interruptible(&info->delta_msr_wait);
}
if ((info->flags & ASYNC_CHECK_CD) && (dstatus & SER_DCD)) {
#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
printk("ttyS%d CD now %s...", info->line,
(!(status & SER_DCD)) ? "on" : "off");
#endif
if (!(status & SER_DCD))
wake_up_interruptible(&info->open_wait);
else {
#ifdef SERIAL_DEBUG_OPEN
printk("doing serial hangup...");
#endif
if (info->tty)
tty_hangup(info->tty);
}
}
if (info->flags & ASYNC_CTS_FLOW) {
if (info->tty->hw_stopped) {
if (!(status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
printk("CTS tx start...");
#endif
info->tty->hw_stopped = 0;
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
return;
}
} else {
if ((status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
printk("CTS tx stop...");
#endif
info->tty->hw_stopped = 1;
info->IER &= ~UART_IER_THRI;
/* disable Tx interrupt and remove any pending interrupts */
custom.intena = IF_TBE;
mb();
custom.intreq = IF_TBE;
mb();
}
}
}
}
static irqreturn_t ser_vbl_int( int irq, void *data)
{
/* vbl is just a periodic interrupt we tie into to update modem status */
struct async_struct * info = IRQ_ports;
/*
* TBD - is it better to unregister from this interrupt or to
* ignore it if MSI is clear ?
*/
if(info->IER & UART_IER_MSI)
check_modem_status(info);
return IRQ_HANDLED;
}
static irqreturn_t ser_rx_int(int irq, void *dev_id)
{
struct async_struct * info;
#ifdef SERIAL_DEBUG_INTR
printk("ser_rx_int...");
#endif
info = IRQ_ports;
if (!info || !info->tty)
return IRQ_NONE;
receive_chars(info);
info->last_active = jiffies;
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
return IRQ_HANDLED;
}
static irqreturn_t ser_tx_int(int irq, void *dev_id)
{
struct async_struct * info;
if (custom.serdatr & SDR_TBE) {
#ifdef SERIAL_DEBUG_INTR
printk("ser_tx_int...");
#endif
info = IRQ_ports;
if (!info || !info->tty)
return IRQ_NONE;
transmit_chars(info);
info->last_active = jiffies;
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
}
return IRQ_HANDLED;
}
/*
* -------------------------------------------------------------------
* Here ends the serial interrupt routines.
* -------------------------------------------------------------------
*/
/*
* This routine is used to handle the "bottom half" processing for the
* serial driver, known also the "software interrupt" processing.
* This processing is done at the kernel interrupt level, after the
* rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON. This
* is where time-consuming activities which can not be done in the
* interrupt driver proper are done; the interrupt driver schedules
* them using rs_sched_event(), and they get done here.
*/
static void do_softint(unsigned long private_)
{
struct async_struct *info = (struct async_struct *) private_;
struct tty_struct *tty;
tty = info->tty;
if (!tty)
return;
if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event))
tty_wakeup(tty);
}
/*
* ---------------------------------------------------------------
* Low level utility subroutines for the serial driver: routines to
* figure out the appropriate timeout for an interrupt chain, routines
* to initialize and startup a serial port, and routines to shutdown a
* serial port. Useful stuff like that.
* ---------------------------------------------------------------
*/
static int startup(struct async_struct * info)
{
unsigned long flags;
int retval=0;
unsigned long page;
page = get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
local_irq_save(flags);
if (info->flags & ASYNC_INITIALIZED) {
free_page(page);
goto errout;
}
if (info->xmit.buf)
free_page(page);
else
info->xmit.buf = (unsigned char *) page;
#ifdef SERIAL_DEBUG_OPEN
printk("starting up ttys%d ...", info->line);
#endif
/* Clear anything in the input buffer */
custom.intreq = IF_RBF;
mb();
retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
if (retval) {
if (serial_isroot()) {
if (info->tty)
set_bit(TTY_IO_ERROR,
&info->tty->flags);
retval = 0;
}
goto errout;
}
/* enable both Rx and Tx interrupts */
custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
mb();
info->IER = UART_IER_MSI;
/* remember current state of the DCD and CTS bits */
current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
IRQ_ports = info;
info->MCR = 0;
if (info->tty->termios->c_cflag & CBAUD)
info->MCR = SER_DTR | SER_RTS;
rtsdtr_ctrl(info->MCR);
if (info->tty)
clear_bit(TTY_IO_ERROR, &info->tty->flags);
info->xmit.head = info->xmit.tail = 0;
/*
* Set up the tty->alt_speed kludge
*/
if (info->tty) {
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
info->tty->alt_speed = 57600;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
info->tty->alt_speed = 115200;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
info->tty->alt_speed = 230400;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
info->tty->alt_speed = 460800;
}
/*
* and set the speed of the serial port
*/
change_speed(info, NULL);
info->flags |= ASYNC_INITIALIZED;
local_irq_restore(flags);
return 0;
errout:
local_irq_restore(flags);
return retval;
}
/*
* This routine will shutdown a serial port; interrupts are disabled, and
* DTR is dropped if the hangup on close termio flag is on.
*/
static void shutdown(struct async_struct * info)
{
unsigned long flags;
struct serial_state *state;
if (!(info->flags & ASYNC_INITIALIZED))
return;
state = info->state;
#ifdef SERIAL_DEBUG_OPEN
printk("Shutting down serial port %d ....\n", info->line);
#endif
local_irq_save(flags); /* Disable interrupts */
/*
* clear delta_msr_wait queue to avoid mem leaks: we may free the irq
* here so the queue might never be waken up
*/
wake_up_interruptible(&info->delta_msr_wait);
IRQ_ports = NULL;
/*
* Free the IRQ, if necessary
*/
free_irq(IRQ_AMIGA_VERTB, info);
if (info->xmit.buf) {
free_page((unsigned long) info->xmit.buf);
info->xmit.buf = NULL;
}
info->IER = 0;
custom.intena = IF_RBF | IF_TBE;
mb();
/* disable break condition */
custom.adkcon = AC_UARTBRK;
mb();
if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
info->MCR &= ~(SER_DTR|SER_RTS);
rtsdtr_ctrl(info->MCR);
if (info->tty)
set_bit(TTY_IO_ERROR, &info->tty->flags);
info->flags &= ~ASYNC_INITIALIZED;
local_irq_restore(flags);
}
/*
* This routine is called to set the UART divisor registers to match
* the specified baud rate for a serial port.
*/
static void change_speed(struct async_struct *info,
struct ktermios *old_termios)
{
int quot = 0, baud_base, baud;
unsigned cflag, cval = 0;
int bits;
unsigned long flags;
if (!info->tty || !info->tty->termios)
return;
cflag = info->tty->termios->c_cflag;
/* Byte size is always 8 bits plus parity bit if requested */
cval = 3; bits = 10;
if (cflag & CSTOPB) {
cval |= 0x04;
bits++;
}
if (cflag & PARENB) {
cval |= UART_LCR_PARITY;
bits++;
}
if (!(cflag & PARODD))
cval |= UART_LCR_EPAR;
#ifdef CMSPAR
if (cflag & CMSPAR)
cval |= UART_LCR_SPAR;
#endif
/* Determine divisor based on baud rate */
baud = tty_get_baud_rate(info->tty);
if (!baud)
baud = 9600; /* B0 transition handled in rs_set_termios */
baud_base = info->state->baud_base;
if (baud == 38400 &&
((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
quot = info->state->custom_divisor;
else {
if (baud == 134)
/* Special case since 134 is really 134.5 */
quot = (2*baud_base / 269);
else if (baud)
quot = baud_base / baud;
}
/* If the quotient is zero refuse the change */
if (!quot && old_termios) {
/* FIXME: Will need updating for new tty in the end */
info->tty->termios->c_cflag &= ~CBAUD;
info->tty->termios->c_cflag |= (old_termios->c_cflag & CBAUD);
baud = tty_get_baud_rate(info->tty);
if (!baud)
baud = 9600;
if (baud == 38400 &&
((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
quot = info->state->custom_divisor;
else {
if (baud == 134)
/* Special case since 134 is really 134.5 */
quot = (2*baud_base / 269);
else if (baud)
quot = baud_base / baud;
}
}
/* As a last resort, if the quotient is zero, default to 9600 bps */
if (!quot)
quot = baud_base / 9600;
info->quot = quot;
info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
info->timeout += HZ/50; /* Add .02 seconds of slop */
/* CTS flow control flag and modem status interrupts */
info->IER &= ~UART_IER_MSI;
if (info->flags & ASYNC_HARDPPS_CD)
info->IER |= UART_IER_MSI;
if (cflag & CRTSCTS) {
info->flags |= ASYNC_CTS_FLOW;
info->IER |= UART_IER_MSI;
} else
info->flags &= ~ASYNC_CTS_FLOW;
if (cflag & CLOCAL)
info->flags &= ~ASYNC_CHECK_CD;
else {
info->flags |= ASYNC_CHECK_CD;
info->IER |= UART_IER_MSI;
}
/* TBD:
* Does clearing IER_MSI imply that we should disable the VBL interrupt ?
*/
/*
* Set up parity check flag
*/
info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
if (I_INPCK(info->tty))
info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
info->read_status_mask |= UART_LSR_BI;
/*
* Characters to ignore
*/
info->ignore_status_mask = 0;
if (I_IGNPAR(info->tty))
info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (I_IGNBRK(info->tty)) {
info->ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignore parity and break indicators, ignore
* overruns too. (For real raw support).
*/
if (I_IGNPAR(info->tty))
info->ignore_status_mask |= UART_LSR_OE;
}
/*
* !!! ignore all characters if CREAD is not set
*/
if ((cflag & CREAD) == 0)
info->ignore_status_mask |= UART_LSR_DR;
local_irq_save(flags);
{
short serper;
/* Set up the baud rate */
serper = quot - 1;
/* Enable or disable parity bit */
if(cval & UART_LCR_PARITY)
serper |= (SERPER_PARENB);
custom.serper = serper;
mb();
}
info->LCR = cval; /* Save LCR */
local_irq_restore(flags);
}
static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
struct async_struct *info;
unsigned long flags;
info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_put_char"))
return 0;
if (!info->xmit.buf)
return 0;
local_irq_save(flags);
if (CIRC_SPACE(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) == 0) {
local_irq_restore(flags);
return 0;
}
info->xmit.buf[info->xmit.head++] = ch;
info->xmit.head &= SERIAL_XMIT_SIZE-1;
local_irq_restore(flags);
return 1;
}
static void rs_flush_chars(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
return;
if (info->xmit.head == info->xmit.tail
|| tty->stopped
|| tty->hw_stopped
|| !info->xmit.buf)
return;
local_irq_save(flags);
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
local_irq_restore(flags);
}
static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
{
int c, ret = 0;
struct async_struct *info;
unsigned long flags;
info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_write"))
return 0;
if (!info->xmit.buf)
return 0;
local_irq_save(flags);
while (1) {
c = CIRC_SPACE_TO_END(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE);
if (count < c)
c = count;
if (c <= 0) {
break;
}
memcpy(info->xmit.buf + info->xmit.head, buf, c);
info->xmit.head = ((info->xmit.head + c) &
(SERIAL_XMIT_SIZE-1));
buf += c;
count -= c;
ret += c;
}
local_irq_restore(flags);
if (info->xmit.head != info->xmit.tail
&& !tty->stopped
&& !tty->hw_stopped
&& !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
local_irq_disable();
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
local_irq_restore(flags);
}
return ret;
}
static int rs_write_room(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_write_room"))
return 0;
return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
static int rs_chars_in_buffer(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
return 0;
return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
static void rs_flush_buffer(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
return;
local_irq_save(flags);
info->xmit.head = info->xmit.tail = 0;
local_irq_restore(flags);
tty_wakeup(tty);
}
/*
* This function is used to send a high-priority XON/XOFF character to
* the device
*/
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_send_char"))
return;
info->x_char = ch;
if (ch) {
/* Make sure transmit interrupts are on */
/* Check this ! */
local_irq_save(flags);
if(!(custom.intenar & IF_TBE)) {
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
}
local_irq_restore(flags);
info->IER |= UART_IER_THRI;
}
}
/*
* ------------------------------------------------------------